Guitar pickups are certainly well known since the first electric guitar appeared in the 1930's. Pickups must be sensitive to the vibrations of the metallic strings used with a guitar, and ideally insensitive to environment electromagnetic noise and to microphonic noise caused by quickly relative movement of pickup components, such as movement in the wires forming the coil of a pickup.
In the prior art, it was quite common to use a coil wound on magnetized pole pieces to form a pickup. Indeed, the first commercial pickups sold by Leo Fender probably had such a design. Later, Les Paul proposed using a pair of stacked coils wound on in-line magnetized pole pieces, with the coils being connected out of phase with each other so as to help cancel environmental noise. Using two coils, either stacked on top of each other, or arranged side-by-side, and connected out of phase with each other became known as hum-bucking since the design was less sensitive to the 60 Hz hum noise found in modern environments. Seymour Duncan also made stacked hum-bucking pickups, but he used a set of common magnetized pole pieces, as opposed to the separate in-line magnetized pole pieces used by Les Paul.
Instead of magnetizing the pole pieces themselves, Rickenbacker used non-magnetized pole pieces. Rickenbacker's earliest pickups featured a horseshoe shaped magnet which surrounded not only the pole pieces and coil, but also the strings of the guitar. By the late 1960's, Rickenbacker used non-magnetic pole pieces in combination with a rather flat, thin ceramic magnet. Such a design was also the subject of Fender's U.S. Pat. No. 4,220,069, the disclosure of which is hereby incorporated herein by reference.
In order to reduce microphonic noise caused by relative movement within a pickup, such as by movement of the wires in the pickup's coil or in the bobbin to plateplate connection, various impregnating media have be used in the prior art, including paraffins and epoxy resins.
For a more complete history of guitar pickups, the reader is referred to Chapter 3 of Guitar Electronics: A Workbook by Donald Brosnac, published by d. B. Music Company, Ojai, Calif., the disclosure of which is hereby incorporated herein by reference.
While the have been many improvements made to guitar pickups over the years, this is still a need for a guitar pickup which is sensitive to the vibrating strings, yet relatively insensitive to environmental hum and not subject to generating microphonic noise. The present pickup has been found to be sensitive to vibrating strings, while still being relatively insensitive to hum and quiet.